Web Services Addressing 1.0 provides a transport-neutral mechanism for
addressing objects in Web services applications built on top of URIs. This
new method is called an endpoint reference, or EPR. EPRs are designed to
solve the issues posed by specific scenarios:

Dynamic generation and customization of service endpoint descriptions,
such as those created for a session id or customer id

Referencing and description of specific service instances that are
created as the result of stateful interactions

Flexible and dynamic exchange of endpoint information in tightly
coupled environments where communicating parties share a set of common
assumptions about specific policies or protocols that are used during the
interaction.

In addition to the addressing function of EPRs, they can serve a role
similar to that of a cookie for Web services interactions. Another special
feature of EPRs is referred to as a metadata bag. The metadata bag allows for
additional information - whether it be a policy statement, a WSDL
description, or Semantic Web data - to be included with the EPR.

EPRs serve as a key component of Web services specifications developed in
a variety of different standards and industry organizations. The W3C work
ensures that these diverse groups have a universal starting point with
regards to addressing Web services messages.

Along with the core
specification, the W3C Web Services Addressing Working Group issued an
accompanying Recommendation, "Web Services
Addressing 1.0 - SOAP Binding". The SOAP binding provides instructions to
developers interested in implementing Web Services Addressing with either the
W3C standard SOAP 1.2 or the earlier SOAP 1.1 version. It specifies security
considerations to use Web Services Addressing safely.

Web Services Addressing 1.0 Facilitates Asynchronous Interactions

Web Services Addressing introduces a way to specify the destination
address reply messages and faults in SOAP messages, taking advantage of
SOAP's versatility in being carried by arbitrary underlying protocols and
being applicable to a wide variety of interaction patterns. This capability
facilitates in particular scenarios with long-running requests.